Typewriting machine



May 22, 1923. 1.456.302

1 W A. DOBSO'N TYPEWRITING MACHINE Filed May 28 1920 I NVENTOR BY ATT NEY.

Patented May 22, 1923. I i a EASGSGZ UNHTED stares iearsn'r orFicE];

WILLIAM A. DOBSON, F HARTFORD, CONNECTICUT, ASSIGNOB TO UNDEBWOOI) TYRE -v WRITER COMPANY, OF NEW YORK, N. IL, A G ORFORATIO N OF DELAWARE.

TYPEWRITING IMACI-IINE.

Application filed May 28, 1920. Serial No. 384,863.

To all whom it may concern: their pivots 12, to pull forwardly on links Be it known that 1, WILLIAM A. DOBSON, 13 to swing type-bars 14 about a pivot 15, a citizen of the United States, residing in to cause, types 16, 17 or 18 thereon to swing Hartford, in the county of Hartford and upwardly and rearwardly against the front State of Connecticut, have invented certain side of a platen20. The platen is supported.

new and useful Improvements in Typewritin a carriage 21 to travel back and forth 60 ing Machines, of which the following is on a rail or bar 22. The key-levers operate a specification. a universal bar 23 to swing the latter about This invention relates to typewriting mathe axis of a rock-shaft 24, to operate suitchines, and more particularly to ribbonable carriage-escapement mechanism (not.

vibrating mechanism therefor. shown). The universal bar 23 also operates 65 The ribbon usually occupies a position beribbon-vibrating mechanism, which may be low the printing point, and is vibrated into like that disclosed in the application of the path of the type-bars as they are swung George WV. Campbell, No. 240,000, filed June toward the platen by their keys. The 14, 1918, (now Patent No. 1,370,281, dated mechanism is usually settable, so as to vary March 1, 1921), to bring a ribbon 25 into 70 the throw of the ribbon to expose different the path of the operated type-bar. The ortions thereof to the types. universal bar 23 is provided with an 'up- Difficulty has been experienced in ribbonwarclly-extending arm 26, which pulls a vibrating mechanism, which is due to the llnk 27 forwardly to rock an intermediate fact that the ribbon is overthrown when the lever 28 about its pivot 30. The intermedi- 75 lower part thereof is used, the overthrowing ate lever 28 is provided with a channelresulting from the momentum of the mechashaped portion 31 forming a groove or slot nism, which causes a partial type-impression 32, into which a pin 33 projects from a ribon the work-sheet. V bon-vibrating lever 34, so that the latter An object of this invention is to prevent may be swung about its pivot 35 by its in- 80 the overthrow of the ribbon. To this end, termediate lever 28, thus causing an inwardthere may be provided, in connection with ly-projecting arm 36 of said ribbon-vibratthe shifting frame, a stop with which the ng lever to move upwardly. The arm 36 ribbon-vibrating mechanism engages when 1s connected to a headed stud '37, extending the maximum throw is imparted thereto. from a ribbon-vibrator 38, which moves up- The relative position between the ribbon wardly with the arm 36 to bring the ribbon vibrating mechanism and the stop therefor 25 to the printing point. may be maintained when the platen is The ribbon-vibrator moves up and down 35 shifted. on a guide 40 fastened to the rail 22 by Other features and advantages will herescrews 41. The guide 40 may comprise inafter appear. a body portion 42 having two forward ex- In the accompanying drawings, tenslons 43 terminating in upwardly extend- Figure 1 is a perspective view of a poring arms44 embracedby fingers 45 of the tion of a typewriting machine, showing the rlbbon-vibrator 38.

invention applied thereto. To guide the lower end of the ribbon- Figure 2 is a fragmentary front View, vibrator 38, the stud 37 projects into a slot showing the lower portion of the ribbon 50 formed in the body portion 42 of the vibrated to the printing point, the platen guide 40. The guide 40 is provided" with 45 being in its lower-case position. lips 51 to engage the upper surface of a Figure 3 is a view similar to Figure 2, cross-bar 52 of the carriage 21 to assist in showing the relation of parts when the lowholding the carriage on the rail 22.

er portion of the ribbon is vibratedto the In Figure 1, the link 27 so connected printing point, while the platen is in its with the intermediate lever that it Wlll imupper-case position. part the minimum throw to the ribbon- The invention is herein illustrated as vibrator when the universal bar is operated,

applied to an Underwood portable typethus bringing the upper part of the ribbon writing machine, in which key-levers 10, to the printing point. The link 27 1s sh ftwhen depressed, swing bell-cranks 11 about able, by a finger-piece 53, to the position indicatedin dotted lines in the right-hand end of a slot 54; in other words, nearer to the fulcrum 30 of the intermediate lever 28,

, and consequently a greater movement is impartedlto the ribbon-vibrating lever by the same depression of the universal bar; thus the lower part of the ribbon 25 is brought to the printing point. lVhen greatest throw is imparted to the ribbonvibrator, there is a tendency for the ribbon- 1 vibrator to overthrow, due to the momentum. of the ribbon-vibrating mechanism,

I and consequently cause a partial type-imgpression on the work-sheet around the platen.

To avoid any possible overthrow of the ribbon-vibrating mechanism, there is provided an adjustable stop which may be in the form of a set-screw 55, threaded into an ear or extension .55 of the extension or horizontal portion 43 of the right-hand guide-arm 4A. The set-screw may be held in place by a check-nut 56 and is located to be engaged by the arm 36 of the ribbonvibrating lever, so as, to arrest the latter when the maximum throw is imparted thereto. 1

I Each type-bar may be provided, as here inbefore stated, with three types 16, 17 and 18, which may be lower-case character's,

,middle-case characters and upper-case characters, respectively. Platen-shifting mechanism, as shown in my Patent No. 1,335,956, dated April 6, 1920, may be provided, which may comprise shift-keys (not shown herein), to shift the platen 20, by means of a platen-frame 57 to which the rail 2 is secured, from lower-case position to middle- .case or upper-case positions. When the platen is thus. shifted, .the ribbon-vibrating lever 34 and the parts associated with the arm 36 thereof areshifted upwardly, thus causing the pin 33 of the ribbon-vibrating lever to occupy any one of the positions L,

M and U in the slot 32, indicated in Figure .2. Thus, it will be seen thatwhile the platen is being shifted, the relative position of the ribbon-vibrator and connected parts remains undisturbed,

Variations may be resorted to wlthin the scope of the invention, and portions of the improvements may be used Without others.

Having thus described my invention, I claim:

1. In a typewriting machine, the combination of a platen, a forked ribbon-vibrator, a guide for, said ribbon-vibrator, a trans verse lever to engage said vibrator centrally and operate the same,a stop for said lever.

,said stop being vadjustably mounted on said guide, platen-shiftingmeans, and a support for said lever and said guide, said support being shiftable with said platen.

2. In a typewriting'machine, the combination of a platen, ribbon-vibrating mechanism comprising a vibrator, a guide for said vibrator, a vibrator-actuating lever fulcrumed at one side of the machine, the throw of said lever being variable to lift the ribbon to various positions, and a stop on said guide in the path of said lever to limit the maximum throw thereof.

3. In a typewriting machine, the combination of a platen, a ribbon-vibrator, a guide for said ribbon-vibrator, said guide comprising a body portion and two arms extending therefrom, said vibrator embracing said arms, a lever to actuate the vibrator, and a stop for said lever, said stop being adjustably mounted on one of said arms.

4. In a typewriting machine, the combination of a platen, a ribbon-vibrator, a guide for said ribbon-vibrator, said guide having a body portion and two arms extending therefrom, each arm comprising a horizontal portion and a vertical portion, said vibrator embracing the vertical portions, a lever to actuate the vibrator, an extension on one of said arms, and a setscrew on said extension to stop said lever.

5. In a typewriting machine, in combination, a platen, a ribbon-vibrator, a forked ribbon-vibrator-guide midway between the sides of the machine, a vibrator-actuating arm pivoted at one side of the machine'and connected at its free end with the vibrator centrally of said forked guide and at the base thereof, and an adjustable stop on the guide to engage said arm adjacent its free enc. I

6. In a typewriting machine, in combination, a platen, a ribbon-vibrator, a guide having a fiat body portion and arms extending at right angles thereto to form overhanging portions, and then parallel to said flat body portion, said vibrator being in front of said body portion and tothe rear of the portions of said arms parallel to said flat body portion, said vibrator embracing said arms, an operating lever fulcrumed at one side of the machine and having one end extending beneath said overhanging portions and. connected centrally to said vibrator, and a'sto'p for said lever adjustably supported by one of said overhanging portions.

WILLIAM A. DOBSON.

V\7itnesses GEORGE W. CAMPBELL, 

